The vast amount of 2D character animation is needed in 2D network game. Because amount of the character animation is very large, the cost of the hand drawn is very high. The visual effect is not good enough. Recently, a popular method is that a scene and a character are created in a 3D environment by three-dimensional modeling technology firstly. The view is fixed. The character is made a few fixed pose in order. Finally, a signal static picture is manually exported. A number of the signal static pictures exported are combined into an animation series for continuous play. That will make an action animation of character.
In addition, the character animation generally includes a head, body, a cloth, a shoot, a weapon, a equipment and so on in the game. For supporting equipment replace, the color change of the hair and cloth, these elements need to be rendered independently. In another word, the 2D picture is generated from the 3D module by the computer. The 2D pictures are real-time spliced in the game. A reference point is needed for splicing two pictures. The name of the reference point is binding point. For example, the weapon binding point determines that the weapon picture will bind specific pixel position of the character body. Recently, the method for generating binding point information is same as the method for generating character animation picture. The binding point is regarded as an element to render in 3D environment. In render process, the other elements are hided. That will get a projection picture for the binding point with a black background. This projection picture is name as binding point bitmap. If the character has a number of binding points, it will render once again until obtain a binding point picture with all of the binding point. In the follow splicing picture process, the intensity data of the pixel in the binding point bitmap as a basis for judging location of the bitmap. The pixel has a highest intensity is determined as the location of the binding point.
Above process for output binding point in bitmap manner by three-dimensional projection is called three-dimensional projection binding point rendering.
In the game development process, the image of the character and feeling of the action to combat always need be modified. And all the action of the character will render again and again. The game always includes a lot of character, such as 8 leading role. Each leading role includes 200 frames and 5 surfaces. Each character has 200*5=1000 pieces of signal frame action picture. The signal frame action pictures are all rendered. In total game, there are 1000*8=8000 pieces of signal frame action picture need to be rendered for the leading role alone. If each signal frame action picture only corresponds to 5 binding point bitmap, the number of the need binding point bitmap will reach 8000*5=40000. These work need to be done manually. That is very tedious. If the character animation is modified, the re-modify work will consume take a long time.
On the other hand, the binding point information output is realized by a ball binding point of a 3D module projecting on a plane surface to generate a 2D image. The binding point projected is not only a pixel, but a number of pixels. A few pixels may have same intensity. When the picture is spliced by reading binding point, the real binding point is hard to be judged from these pixels. The binding equipment or other elements may jitter in the spliced picture. That means the binding point position is incorrect. The typical method for solving this problem is that the jitter binding point bitmap is modified manually though PS method. The amount of the binding point bitmap is very large. The modification work is very hard.
Anyway, the binding point information in bitmap manner is generated by typical three-dimensional projection binding point rendering is very large. The data is hard to be modified and maintained. In the follow step for splicing picture, the location of the binding point is easily misjudged. That will generate a phenomenon of binding point jitter.